Date: Thu, 17 Oct 2024 16:00:03 -0400
From: Bruce Momjian <bruce@momjian.us>
To: Koen De Groote <kdg.dev@gmail.com>
Cc: pgsql-docs@lists.postgresql.org
Subject: Re: Logical replication - initial data synchronization
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On Thu, Oct 17, 2024 at 09:57:04PM +0200, Koen De Groote wrote:
> I would still add that the snapshot and data copying is handled by postgres
> itself. That was the big question I was stuck with:"Who is taking this
> snapshot? Do I have to do it? Will they explain how?"
> 
> Because it's left in the middle who does it. Once you know how logical
> replication works, it's obvious, re-reading the documentation I know what to
> expect, but that's only because I've already done it a few time snow.
> 
> As someone just starting and reading the documentation, it was a stumbling
> block for me.
> 
> To me,
> 
> >   When logical replication of a table typically starts, a snapshot is
> >   taken of the table's data on the publisher database and copied to the
> >   subscriber
> 
> Does not clarify that.
> 
> It's the reason I created this mail: I would like it stated explicitly that the
> database process takes care of this for us.

Well, you are the first person to report this confusion, and we can't go
around explaining what Postgres does and does not do in each section.  I
would need to hear from other people that this is confusing before
making it explicit.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  When a patient asks the doctor, "Am I going to die?", he means 
  "Am I going to die soon?"